Nano-graphite Enhanced Thermal Conductivity of Decanoic Acid-Tetradecyl Alcohol Composite Phase Change Material
WANG Bo1, ZHU Xiaoqin1, HU Jin2, CHANG Jinghua1, CHEN Yang1, SHI Jie1
1 Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500 2 Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650500
Abstract: As a common organic phase change material, fatty acids show advantages of cyclic melting/crystallization stable thermal properties, non-to-xicity, non-corrosiveness etc. Nevertheless, the low thermal conductivity coefficient of fatty acid systems (0.1—0.3 W·m-1·K-1) blocks their widespread industrial applications. For the sake of improving the thermal conductivity of decanoic acid (CA)-tetradecyl alcohol (TA) composite phase change material, composite phase change material matrix with CA and TA molar ratio of 7∶3 was selected, and nano-graphite with diverse mass fractions was added to prepare decanoic acid-tetradecyl/nano-graphite composite phase change material system. It was discovered that, a relatively stable suspension could be achieved when the added mass fraction of nano-graphite was 0.1%—0.9%. SEM, DSC and Hot Disk were employed to characterize the main thermophysical properties of the obtained composite phase change material. As can be seen from the analysis results, decanoic acid-tetradecyl/nano-graphite composite phase change material showed a substantial increase of the thermal conductivity coefficient while its phase change temperatures and latent heats maintained almost unchanged compared to the matrix. The decanoic acid-tetradecyl alcohol/nano-graphite composite phase change material with nano-graphite mass fraction of 0.6% presented optimal comprehensive property, showing 39.5% and 35.2% increase in its thermal conductivity coefficients of solid and liquid states, and its phase change tempera-ture and latent heat were 20.42 ℃ and 154.25 kJ/kg, respectively, indicating a satisfactory thermal stability.